Just thought I would drop an update to my quest for power which started nearly 3years ago. I attempted to tune reprogram my 2008 jaguar XKR 4.2 after doing a 1.5lb pulley upgrade. Quick recap: I tried "OE tuning" which lost hp from stock 359rwh on a Mustang Dynometer. Tried Eurochatged which gained a whoping 7rwh lol, had to politely ask for most of my money back. I got frustrated and decided to go into tuning myself and after a year of learning and figuring out the ECU I developed my own tune for these cars. I did also install 200 cellcell flow cats. Went back to the same Dyno today and got 433rwh but that might have been in 3rd gear so we will use the more conservative number of 426rwh which was in 4th gear at a gain of 67rwh . Torque reading in 3rd gear where a little higher at 580rwt and car down shifted, so we will discard them and use 4th gear only at around 430rwt but I suspect they are higher looking at the torque curve in 3rd gear.
Keep in mind this is Mustang Dynometer which typically reads lower compared to Dynojet. Either way if using typical for Mustang Dyno 20% drive train loss that would put me at 511 crank hp, which is an amazing gain for a 4.2 engine .
I'm happy to see fruits of my hard work pay off ,😁😁

 

That's great! Can you share details of where you bought the parts (pulley, cats, etc.)? Will you make your custom tune available to others? Any warning lights? Do you have a Quaife LSD?

 

Pulley is from Eurotoys 1.5lb, high flow cats I purchased from a member on here he custom makes them and does a great job "FreakinJag" I think that the right name. Im not planning to get LSD yet since traction with my tune is decent, with not great tires I could still get 1.89 60ft and with better tires I should be able to get It down to 1.79 or better. Will be going to drag strip at Vegas on Friday night , will see what I get with a better tire setup. Tune is available for sale and already have a happy XkR driver who is a forum member on here.
Re warning lights , I can modify the tune for high flow cats or no cats , you will not have any warning lights. Can also tune Na 4.2 engine with same ecu as the setup is very similar.

 

Do you have any other graphs? The one posted has some huge concerns and I would not push it until they are remedied.

#1 is the huge power drop down low right as the A/F leans out. Definitely smells like detonation sensors pulling power. Not enough fuel and too much timing brings on detonation. That's a tune that will kill and engine if left alone. Head gasket if you are lucky.

#2 is the power loss and boost drop at 4500 rpm. Throttle closing or belt slippage? Linear boost curve looks like throttle closing versus slip. Something in the tune is shutting the engine down.

Peak numbers are OK for bragging rights but the area under the curve is where an engine lives or dies. Your torque should be similar to your boost curve, nice and linear. Your boost is increasing but the torque curve is decreasing before that second dip. Again, something is pulling power out because you aren't to the point that flow restrictions would limit power.

What was your peak boost?

 

Ranchero with all due respect , not sure why you would post conclusions if you don't know what you're looking at, if you haven't seen many raw untouched up dynos. There's no power loss no AFR leaning out what you looking at is a car downshifting

 

I've seen a bunch of dyno runs, hundreds and honestly I don't know of any competent shop that wouldn't hold the tranny in one gear for a full pull if the car would allow it. Select a gear that doesn't spin the tires and let the accelerometers do their calculations. Since the graph doesn't show wheel speed I assumed you have issues. Still doesn't address what's happening at 4400 rpm or what the peak boost was. I'm also curious why they started the pull so high in the RPM band. Torque is where a tune really matter. Even allowing for a downshift that curve doesn't look happy and begs to have some questions answered.

I feel from your most recent reply that you were only looking to toot your own horn. Hopefully I'm wrong and you are just typing impatiently from a phone. Just hate to see you nuke your engine and I think there is a still some unlocked performance lurking in there.

Good luck with it.

 

Ranchero your asking for peak boost numbers even though your looking right at them. Lower line AFR , one higher up is boost line

 

Yeah, I see the line, just no scale (unlike AFR and Wheel torque). With most dyno programs you can offset the scale so the lines don't overlap and become confusing. If the bottom horizontal line is 0 psi then you made peak torque at 5 psi of boost and that really doesn't compute well. If the scale is offset you had more boost than indicated on the graph. Where were they reading it? You lost boost at 4500 rpm so the processor was holding the engine back.

I've seen a bunch of graphs and witnessed some pretty amazing runs so this isn't my first rodeo. Dyno's are good at helping a person understand what their engine is doing if they understand the numbers. You are brewing your own tune and so far you really haven't answered any questions about the sheet you posted. Honestly the more you reply the more it feels like you don't understand what you were shown during the session. Not trying to be confrontational so don't take it that way. I absolutely love diagnosing dyno graphs and other will chime in as they see this thread. You had some interesting stuff happening during that pull.

 

Ranchero to make things a little more clear
lower line, ignore (lambda ratio), one above that is AFR, one above AFR is boost. Hope that makes things a little clearer for you . 4th gear run. As to why started at higher rpm, is due our cars habbit of kicking into a lower gear

 

Well done, that is really impressive and that last graph looks a lot better! I would love to look through a tune file and understand how it all works but I wouldn't know where to start.

Will that be another 1/8 mile or will you be doing a 1/4 this time? It would be good to see 1/4 mile results as that gives a better indication of power.

No idea what the make of the dyno was that my X150's have been on but I found that 9.1% was the drivetrain loss on my '10 XKR so 20% may be a bit high. Still a good result though.

 

How did you get on?

The best terminal speed I ever got with my '07 XKR for the 1/4 mile was 113.19mph and 109.89mph when stock so I will be interested to hear what you got.

 

Here's the dyno run of my 5.0l done last week.

TBH a little disappointed given it's running k&n's and a smaller pulley and a modded exhaust (no backbox) but advised it still has the standard map.

I bought my car as stock so had no idea on the above, so a bonus to start in a potentially better place!



Just for comparison sake and don't mean to hijack thread.

A little nose chatter from front of SC, which I'll have looked at at the same time SC is serviced in Spring

 

That's a nice flat torque curve. Nothing to be unhappy about.

 

True but it seems a shame not to have a decent tune put on it?

Clearly it can take it as also has an updated/larger intercooler.

Perhaps may leave until the e-diff/tranny service in Spring, then will know that everything's at optimal

 

So maybe you guys can help me on my chart reading as I have not seen to many dyno run results. The way I read this is that max torque is at about 3300 RPM and it is around 440 ft. lbs while the max HP is around 360 BHP at 6200 RPM. Am I reading this right and if so why am I not seeing the 510HP . Just curious.

 

yes you are correct . and i believe some of the reason is you are reading Wheel HP (HP) vs BHP flywheel HP . so add you prescription percentage to that .
17% is what i was taught . although with that, this is still short a few ponies (like 90) for sure . as i see it too.
that is not good .

 

It all depends on the dyno. They are better for comparing before and after numbers rather than real world numbers.

My '10 XKR showed 343.6KW/463rwhp on a dyno when stock so I calculated the drive train loss to be around 9.1% on that dyno. After putting the XKR-S tune and mid pipe on the car the dyno was showing 375KW/502.8rwhp which would put it at 553bhp so 9.1% may still be a little on the high side.

Torque was 452lb-ft/614Nm when stock and around 497lb-ft/674Nm after fitting an XKR-S tune.

It has had a few more mods since then

 

Yes was concerned too, tester said the 493 was respectable and higher than other 5.0 SC's he's seen. Appreciate that 493 is less than 4% down on 510 and that dyno does a standard conversion for drive train. So it can measure rpm accurately but typically conversion is 18%, but this can vary per car. Tester said he could compensate this by manually changing the parameters but I was happy as was.

On other threads I've read of jag 5.0SC's the loss is actually more like 11% so optimistically mine may be running 7% over 510 which could be 545, which is exactly the figure I would expect for the upgrades currently on the car.

Appreciate that there is no authority that calibrates dyno's like there is for emissions. So some places will calibrate to satisfy customers in search of power and a smile! I prefer that it was kept honest.

 

They do sort of "calibrate" for temp and pressure changes as the engine typically performs better with cooler denser air. The engine RPM per tire RPM equation is important because they are only measuring the tires ability to accelerate a given drum weight. The faster it accelerates, the more torque your drivetrain is applying to the drum. Horsepower is just an equation of torque x RPM.

Ideally you want to see a nice consistent torque curve. Any dips or spikes on an electronic controlled system is an indication the tune is most likely doing "something" to the drivetrain. Marky, yours is pulling some power starting at 3500. That torque curve should be around the 450 mark at 4k. The trick is to monitor the air flow, manifold pressures and fuel state to help determine what the tune's strategy is at that RPM and pressure. Is there a mechanical deficiency or is it simply the tune doing "something" for "some odd reason". The key thing is your curve is stable unlike Alex's. Your tune is stable and pretty happy.

Without the positive displacement blower adding air the torque curve would be much more inclined similar to the HP one.

 

I guess where it was a little confusing to me is that the torque scale on the left is stated in FLYWHEEL measurement so I would have thought that the HP rating was based on flywheel which in my mind is BHP. Just trying to sort it out. Thanks.